Storage type broadcast system, transmitter and receiver

ABSTRACT

Providing a broadcast system wherein storage of contents on the receiving side and use restriction on the stored contents, etc. can be performed per service provided by contents providers. In a storage-based digital broadcast system wherein contents transmitted from a sending side are stored on a receiving side then reproduced, the sending side transmits service structure information for describing relational structure between services provided by contents providers and reference information for associating the contents with the service structure information in advance, and the receiving side receives and stores service structure information and reference information and uses the received service structure information and reference information to manage storage of contents. It is possible to control contents per service based on service structure information and information that can be reorganized from reference information.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a storage-based digital broadcastsystem that receives and stores data contents and AV (Audio-Visual)contents on the receiving side sent from the sending side and reproducesthe data contents and AV contents, etc. in viewing, and a transmitterand a receiver used in the system, and in particular to a storage-baseddigital broadcast system wherein storage of contents on the receivingside and use restriction on the stored contents, etc. can be controlledper service provided by contents providers, and a transmitter and areceiver used in the system.

2. Description of Related Art

In digital broadcasts, storage-based broadcast systems have beendeveloped where programs and contents transmitted from the sending sideare received and stored on the receiving side and users reproduce toview the programs and contents when it is convenient for them.

In this broadcast system, broadcast programs and the associated programadditional information (contents) are transmitted and SI (ServiceInformation) such as EIT (Event Information Table) and LIT (LocaleventInformation Table) to define program scenes and ERT (Event RelationTable) to define relationship between scenes are broadcast as guidanceinformation on programs, etc. On the receiving side, it is possible toreceive and store broadcast programs and contents and use SI toreproduce for example only news programs from among stored programs andcontents or to view a particular scene of a program.

In the future digital broadcasts, a broadcast form is expected whereproviders that create and provide contents will be separated frombroadcast operators and that broadcast operators will only multiplex andtransmit contents provided by contents providers.

Information indicating a contents provider and information on theservices to which the contents belong will be described for individualcontents.

The Japanese Patent Laid-Open No. H07-177109/(1995) indicates addingcodes to a plurality of information pieces and determining the priorityof display that is based on each code. A code used in this disclosurehas an inherent meaning so that the meaning of the code cannot bechanged later.

Terms used herein will be defined below.

AV (Audio-Visual) data: Stream format data such as image, voice andsubtitle data.

Data contents: Non-stream format data associated with broadcastprograms. For example, HTML, XML, BML, moving pictures (MPEG and MOV),still pictures (JPEG, GIF) are included. Individual contents can beidentified using identifiers.

AV contents: AV data related to data contents among AV data. IndividualAV contents can be identified using identifiers.

Contents: Data contents and AV contents, which partially reference eachother.

Service: Information that groups contents.

In related art storage-based broadcast system s, it is not easilypossible to automatically store in a receiver the contents that belongto a service provided by a contents provider, nor set or change thevalidity term of contents stored in the receiver for each serviceprovided by the contents provider.

In case wishing to execute such processing in a related art system, itis necessary to describe information on the contents provider and theservice to which the contents belong for individual program and all thecontents. This results in transmission of huge data thus worsening thetransmission efficiency.

In a related art system, it is impossible to describe the relationshipbetween a plurality of contents providers to which the contents arerelated, or describe the relationship between a plurality of programs orcontents that relate to each other.

In case a single provider is concerned, the contents are transmitted invarious forms from various broadcast operators or in various serviceforms from a single broadcast operator, or separately with shiftedtimings due to limited transmission bandwidth. In this way, it isdifficult to receive contents with the structure (relationship betweencontents) intended by the provider maintained.

Appending data that indicates the corresponding service to contentsprevents change of service.

The invention solves such problems and aims at providing a broadcastsystem where storage of contents on the receiving side and userestriction on the stored contents, etc. can be implemented per serviceprovided by contents providers and a transmitter and receiver used inthe system.

BRIEF SUMMARY OF THE INVENTION

According to the invention, in a stored digital broadcast system wherecontents transmitted from the sending side are stored on the receivingside then reproduced or displayed, the sending side transmits servicestructure information for describing relational structure betweenservices provided by contents providers and reference information forassociating the contents with the service structure information, and thereceiving side uses the received service structure information andreference information to manage storage of contents.

A transmitter according to the invention comprises service structureinformation generating means for generating service structureinformation representing the relational structure between servicesprovided by contents providers, reference information generating meansfor generating reference information associating contents with servicestructure information, service information adding means for addingreference information to service information, andmultiplexing/transmission means for multiplexing service informationcontaining reference information and service structure information intodata contents and AV data and transmitting the resulting data.

A receiver according to the invention comprises receiving/demultiplexingmeans for demultiplexing contents, service structure informationdescribing the relational structure between services provided bycontents providers and service information containing referenceinformation associating contents with service structure information fromreceived signals, contents storage means for storing demultiplexedcontents, service structure storage means for storing demultiplexedservice structure information, service information storage means forstoring demultiplexed service information, and service management meansfor managing storage of contents by using service structure informationand reference information.

Thus, it is possible to control contents per service based on servicestructure information and information that can be reorganized fromreference information.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing the configuration of a broadcastsystem according to a first embodiment of the invention;

FIG. 2 is a flowchart showing the operation of a transmitter of abroadcast system according to the first embodiment;

FIG. 3 is a flowchart showing the operation of service structureinformation generating means of the transmitter according to the firstembodiment;

FIG. 4 is a flowchart showing the operation of contents informationinput means of the transmitter according to the first embodiment.

FIG. 5 is a flowchart showing the operation of reference generatingmeans of the transmitter according to the first embodiment;

FIG. 6 is a flowchart showing the operation of service informationadding means of the transmitter according to the first embodiment;

FIG. 7 is a flowchart showing the operation of a receiver according tothe first embodiment;

FIG. 8 is a flowchart showing the operation of service creation viareception in the receiver according to the first embodiment;

FIG. 9 is a flowchart showing the operation of service generation viauser's input in the receiver according to the first embodiment;

FIG. 10 shows data addition service structure information according tothe first embodiment;

FIG. 11 shows data addition service structure information with the dummyroute at the top according to the first embodiment;

FIG. 12 shows other data addition service structure informationaccording to the first embodiment;

FIG. 13 shows service structure information according to the firstembodiment;

FIG. 14 shows reference information according to the first embodiment;

FIG. 15 shows data structure produced by service structure informationgenerating means of the transmitter according to the first embodiment;

FIG. 16 shows service structure information transmitted by thetransmitter according to the first embodiment;

FIG. 17 is a flowchart showing the operation of service generation viareception in the receiver according to a second embodiment;

FIG. 18 is a block diagram showing the configuration of a receiveraccording to a third embodiment of the invention;

FIG. 19 is a flowchart showing the operation of a receiver according tothe third embodiment;

FIG. 20 shows service information with an automatic storage flagappended according to the third embodiment;

FIG. 21 shows data addition service structure information with theautomatic storage flag appended according to the third embodiment;

FIG. 22 is a block diagram showing the configuration of a receiveraccording to a fourth embodiment of the invention;

FIG. 23 is a flowchart showing the operation of a receiver according tothe fourth embodiment;

FIG. 24 shows data addition service structure information received bythe receiver according to the fourth embodiment;

FIG. 25 shows data addition service structure information received bythe receiver according to the fourth embodiment and stored real data;

FIG. 26 shows service structure information for exclusive storage areamanagement according to a fifth embodiment of the invention;

FIG. 27 shows service structure information for validity term managementaccording to a fifth embodiment;

FIG. 28 shows service structure information for stored chargingmanagement according to a fifth embodiment;

FIG. 29 shows service structure information for exclusive storage areamanagement via node specification according to the fifth embodiment ofthe invention;

FIG. 30 shows service structure information for automatic storageaccording to the fifth embodiment of the invention;

FIG. 31 shows service structure information for automatic storage vianode specification according to the fifth embodiment of the invention;

FIG. 32 shows service structure information for automatic storage vianode specification from the receiving side according to the fifthembodiment of the invention;

FIG. 33 shows service structure information for determining the identityof contents according to the fifth embodiment of the invention;

FIG. 34 shows an example of service implementation in a broadcast systemaccording to a sixth embodiment;

FIG. 35 shows service structure information reproduced by a receiveraccording to the sixth embodiment;

FIG. 36 shows items to be defined by an information provider;

FIG. 37 shows an example of creating ERT according to the sixthembodiment;

FIG. 38 shows an example of contents identification by a broadcastoperator;

FIG. 39 shows an example of creating reference descriptors for contentsA, B according to the sixth embodiment;

FIG. 40 shows an example of creating a reference descriptor for contentsC according to the sixth embodiment;

FIG. 41 shows an example of creating a reference descriptor for contentsD according to the sixth embodiment;

FIG. 42 shows the expanded EIT data contents descriptor according to thesixth embodiment;

FIG. 43 shows description in the storage-based broadcast service relatedinformation;

FIG. 44 shows the EIT data structure;

FIG. 45 shows the data structure of the data contents descriptor;

FIG. 46 shows the data structure of ERT;

FIG. 47 shows the data structure of the reference descriptor.

DETAILED DESCRIPTION OF THE INVENTION

Referring to numerals in the figures, 10 represents service transmitter,11 service structure information generating means, 12 contentsinformation input means, 13 reference information generating means, 14service information adding means, 15 service structure informationstorage means, 16 service information storage means, 17 data contentsstorage means, 18 AV data storage means, 19 service structureinformation transmission means, 20 service information transmissionmeans, 21 data contents transmission means, 22 AV data transmissionmeans, 23 multiplexing means, 30 service receiving means, 31receiving/demultiplexing means, 32 service structure information storagemeans, 33 service information receiving means, 34 data contentsreceiving means, 35 AV data receiving means, 36 service structureinformation storage means, 37 service information storage means, 38 datacontents storage means, 39 AV data storage means, 40 service managementmeans, 41 service output means, and 42 user input means.

In the first embodiment, a broadcast system consisting of a servicetransmitter 10 and a service receiver 30 will be described referring toFIG. 1. A contents provider groups contents to be provided (classifiescontents into services) and passes the contents of each service to abroadcast operator for broadcasting. The service transmitter 10transmits the contents together with additional information andcomprises AV data storage means 18 for storing AV data provided by thecontents provider, contents storage means for storing data contentsprovided by the contents provider, service structure informationgenerating means 11 for generating service structure informationcontaining structure information (service structure information)specifying the relationship between the data provider and the contentsand the relationship between services as well as information indicatingthe type of the structure information, service structure informationstorage means 15 for storing the service structure information, contentsinformation input means 12 for inputting an identifier (contentsidentifier) for identifying the contents, reference generating means 13for generating information (reference information) to associate contentsidentifiers grouped into services in the service structure information,service information adding means 14 for adding reference information toservice information (SI or PSI (Program Specific Information) fortransmitting programs), service information storage means 16 for storingservice information containing the reference information, AV datatransmission means 22 for extracting AV data to be sent from AV datastorage means 18, data contents transmission means 21 for extractingdata contents to be sent from data contents storage means 17, serviceinformation transmission means 20 for extracting service information tobe sent from service information storage means 16, service structureinformation transmission means 19 for extracting service structureinformation to be sent from service structure information storage means15, and multiplexing means 23 for selecting AV data, data contents,service information and service structure information about to be sentbased on the service information received in advance from the serviceinformation transmission means 20, converting the information torespective transmission formats to correspond to transmission paths, andmultiplexing and transmitting onto transmission paths the data astransmission AV data, transmission data contents, transmission serviceinformation and transmission service structure information.

The multiplexing means converts, for example, AV data to PES data, datacontents to object carousels or data carousels (DDB, DII, etc.) or eventmessages as DSM-CC Section, service information to SI/PSI data structure(PAT, PMT, NIT, SDT, EIT, various descriptors, etc.) conforming to theARIB-STD B10 version 1.2, and service structure information to ERTconforming to the ARIB-STD B10 version 1.2. The service structureinformation may be converted to XML as data contents for transmission.

AV data stored in the AV data storage means 18 may correspond to eachprogram on a one-to-one basis, one-to-many basis or many-to-many basis.

The service receiver 30 comprises receiving/demultiplexing means 31 forreceiving data transmitted from the service transmitter 10 anddemultiplexing the data into AV data, data contents, service informationand service structure information, AV data receiving means 35 forconverting transmission AV data received from thereceiving/demultiplexing means 31 to AV data to be stored/managed, datacontents receiving means 34 for converting transmission data contentsreceived from the receiving/demultiplexing means 31 to data contents tobe stored/managed, service information receiving means 33 for convertingtransmission service information received from thereceiving/demultiplexing means 31 to service information to bestored/managed, service structure information receiving means 32 forconverting transmission service structure information received from thereceiving/demultiplexing means 31 to service structure information to bestored/managed, AV data storage means 39 for storing converted AV data,data contents storage means 38 for storing converted data contents,service information storage means 27 for storing converted serviceinformation, service structure information storage means 36 for storingconverted service structure information, service management means forreading AV data, data contents, service information and servicestructure information and performing per-service processing based on thetype of the service structure information, user input means 42 for theuser to enter instructions, and service output means 41 for outputtingdata read by the service management means 40 according to theinstruction entered by the user.

Next, details of service structure information and reference informationwill be described.

The service structure information represents a contents provider and oneor more services provided by the contents provider in a tree structureas shown in FIGS. 10, 11 and 12. Concerning the services in the servicestructure information, service structure information that associatesgrouped data contents or AV contents is referred to as data additionservice structure information. In this case, the relationship betweendata contents or AV contents and the nodes of a tree structure thatgroups them is referred to as reference information.

For service structure information in FIG. 10, Contents Provider 1 is atthe top of a tree. Four services, Service A, Service B, Service C andService D are child nodes of Contents Provider 1. Data details of theservice structure information are shown in FIG. 13

Reference information shows that AV Content 1, Data Content 1 and DataContent 2 belong to Service A, Data Content 3 to Service B, AV Content2, AV Content 3, Data Content 4, Data Content 5 and Data Content 6 toService C, and AV Content 4 to Service D. Data details of the referenceinformation are shown in FIG. 14.

For example, Data Content 1 is a data content provided by ContentsProvider 1 and belongs to Service A provided by Contents Provider 1. AVContent 4 is an AV content provided by Contents Provider 1 and belongsto Service D provided by Contents Provider 1.

Data addition service structure information in FIG. 11 differs from thedata addition service structure information in FIG. 10 in terms ofpositioning of Contents Provider 1 in the tree structure. In FIG. 11,Contents Provider 1 is not at the top of the tree of data additionservice structure information but positioned as a particular node in thetree structure. Meaning of Service A, Data Content 1 or AV Content 4 isthe same as in FIG. 10. Representation in FIG. 11 may be used instead ofFIG. 10.

FIG. 12 shows a service structure information where hierarchicalrelationship is found between services. In the figure, Service D andService E are child elements of Service C.

Processing of the service transmitter 10 will be described.

FIG. 2 shows the processing procedure of the service transmitter 10.

Step 1001: The service structure information generating means 11generates service structure information as shown in FIGS. 10, 11 and 12.Particular processing procedure will be described later.

Step 1002: Next, the contents information input means 12 inputs contentsinformation. Particular processing procedure will be described later.

Step 1003: The reference generating means 13 generates referenceinformation to associate service structure information generated in step1001 with contents information input in step 1002. Particular processingprocedure will be described later.

Step 1004: The service information adding means 14 adds referenceinformation generated in step 1003 to service information such as SI andPSI. Particular processing procedure will be described later.

Step 1011: The service information transmission means 20 selects serviceinformation about to be sent from the service information storage means16.

Step 1012: The service information transmission means 20 determineswhether to transmit the service information.

Step 1013: The service information transmission means 20 passes theservice information to the multiplexing/transmission means 23.

Step 1021: The service structure information transmission means 19selects service structure information about to be sent from the servicestructure information storage means 15.

Step 1022: The service structure information transmission means 19determines whether to transmit the service structure information.

Step 1023: The service structure information transmission means 19passes the service structure information to themultiplexing/transmission means 23.

Step 1031: The AV data transmission means 22 selects AV data about to besent from the AV data storage means 18.

Step 1032: The AV data transmission means 22 determines whether totransmit the AV data.

Step 1033: The AV data transmission means 22 passes the AV data to themultiplexing/transmission means 23.

Step 1041: The data contents transmission means 21 selects data contentsabout to be sent from the data contents storage means 17.

Step 1042: The data contents transmission means 21 determines whether totransmit the data contents.

Step 1043: The data contents transmission means 21 passes the datacontents to the multiplexing/transmission means 23.

Step 1051: The multiplexing/transmission means 23 converts receivedservice information, service structure information, AV data and datacontents to transmission formats predetermined by the respectivetransmission paths, multiplexes the data according to transmission timesand transmits respective data onto transmission paths. A transmissionschedule may be appended to arbitrary service structure information andselection may be made according to the transmission schedule in step1021. Also, a transmission schedule may be appended to arbitrary datacontents and selection may be made according to the transmissionschedule in step 1041.

Steps 1011, 1021, 1031 and 1041 depend on transmission times ofrespective data and are processed asynchronously.

Conversion of data to transmission formats in step 1051 may be made in aprocess before step 1051.

Processing of the service structure information generating means 11 isshown in the flowchart of FIG. 3.

Step 1101: The contents provider inputs information on the services togroup data contents stored in the data contents storage means 17 and AVdata stored in the AV data storage means 18 to the service structureinformation generating means.

Step 1102: The contents provider inputs the structure between theservices and the type of the service structure information at the sametime. The service structure information generating means 11 generatesservice structure information based on this information.

Step 1103: The service structure information generating means 11 storesthe service structure information in the service structure informationstorage means 15.

Via this step 1101, step 1111 in FIG. 15 is generated. Via the step1101, step 1112 in FIG. 15 is generated. An example of description ofservice structure information in step 1112 in FIG. 15 is shown in FIG.16.

The type to be appended to service structure information is used toidentify the application activated in the receiver. A document (script,etc.) describing the processing that can be interpreted by the receivingside may be appended to service structure information as a type itself.Or, the contents of a document (data contents, script, etc.) describingthe processing that can be interpreted by the receiving side may betransmitted as data contents and an identifier to identify the documentmay be appended as a type to the service structure information.

Next, processing of the contents information input means 12 is shown inthe flowchart of FIG. 4.

Step 1201: In case input of contents information is not complete,

Step 1202: The contents information input means 12 selects arbitrarycontents from the contents storage means 17, 18.

Step 1203: The contents information input means 12 selects whether toinput contents identifiers or information on the contents for theselected contents, and inputs the contents information. The input ismade manually or automatically. In case data is input,

Step 1204: The contents information input means 12 stores the inputcontents information in the contents storage means 17, 18 incorrespondence with the contents.

Step 1205: When input of contents information is complete, the contentsinformation input means 12 passes the contents identifiers orinformation on the contents to the reference generating means 13.

Next, processing of the reference generating means 13 is shown in theflowchart of FIG. 5.

Step 1301: In case generation of reference information is not complete,

Step 1302: The reference generating means 13 selects an arbitrarycontents identifier from among the contents identifiers input from thecontents information input means 12.

Step 1303: In case the contents identifier belongs to the service in theservice structure information,

Step 1304: The reference generating means 13 inputs the contentsidentifier via manual procedure in the node in the service structureinformation and generates reference information representing therelationship between the node and the contents identifier.

Step 1305: When generation of the reference information is complete, thereference generating means 13 passes the reference information generatedin step 1304 to the service information adding means 14. An example ofthe reference information is shown in FIG. 14.

Processing in steps 1302 and 1304 may be automatic. In this case, allthe contents identifiers may be selected in order in step 1302 and arelationship between the nodes and the contents identifiers in theservice structure information may be configured based on the informationappended to the contents in advance.

Next, processing of the service information adding means 14 is shown inthe flowchart of FIG. 6.

Step 1401: In case addition of reference information to serviceinformation is not complete,

Step 1402: The service information adding means 14 selects an unselectedcontents identifier from the reference information.

Step 1403: The service information adding means 14 identifies whetherthe contents identifier is related to an existing event (program).

Step 1404: In case the contents identifier is related to an existingevent, the service information adding means 14 selects serviceinformation where the related event (program) is described from theservice information storage means 16.

Step 1405: The service information adding means 14 appends referenceinformation consisting of the contents identifier and node informationto the description of the event (program) in the selected serviceinformation.

The procedure is repeated until addition of reference information toservice information is complete. In this way, the service informationadding means 14 creates a set of an arbitrary program and contentsrelated to the program and associates the reference information on thecontents with the data describing the information on the program in theservice information storage means 16.

Next, processing of the service receiving means 30 will be described.FIG. 7 shows the processing procedure of the service receiving means 30.

The procedure assumes that the power to the service receiving means 30is turned ON. In this case,

Step 2001: The service receiving means 30 determines whether the user'sinput has been made on the receiving side.

Step 2002: In case it has not been made, the service receiving means 30determines whether data has been received from a transmission path. Incase data has been received, the service receiving means 30demultiplexes the received data.

Step 2003: In case received data contains AV data,

Step 2004: The service receiving means 30 stores the AV data in the AVdata storage means 39.

Step 2005: In case received data contains data contents,

Step 2006: The service receiving means 30 stores the data contents inthe data contents storage means 38.

Step 2007: In case received data contains service information,

Step 2008: The service receiving means 30 stores the service informationin the service information storage means 37.

Step 2009: In case received data contains service structure information,

Step 2010: The service receiving means 30 stores the service structureinformation in the service structure information storage means 36.

Step 2011: The service management mean 40 uses the data stored in steps2004, 2006, 2008 and 2010 to perform internal processing. Details of theinternal processing will be described later.

Step 2012: The service management means 40 performs internal processingin case the user has input data from the user input means 42. Detailswill be described later.

Step 2013: The service management means 40 determines whether to outputthe results of the internal processing in steps 2011 and 2012.

Step 2014: The service management means 40 outputs the results of theinternal processing from the service output means 41.

The AV data storage means 39 may store AD data in the stream form orconvert the AV data to a file format for moving picture files such asMPEG or MOV for storage.

Next, internal processing via data reception by the service managementmeans 40 in step 2011 is shown in FIG. 8.

Step 2101: In case internal processing for all the types appended to theservice structure information stored in the service structureinformation storage means 36 is cot complete,

Step 2102: The service management means 40 selects an unselected type.

Step 2103: The service management means 40 executes processing of theapplication identified by the type.

In this way, the service receiver 30 executes the application identifiedby the type of service structure information and is terminated whenexecution of the application is complete.

The service management means 40 has the application for the internalprocessing installed therein. For example, storage area control isperformed to control the area to store data for each node in thereceived service structure information as the internal processing of theapplication. In case contents appended to the node cannot be stored inthe storage area determined for the node, storage of the contents isrestricted or contents validity control is made where a common validityterm is determined for the contents appended to the node. A particularexample will be given later.

Internal processing that accompanies the user's input is shown in FIG.8.

Step 2201: When the user selects an arbitrary node (service) in theservice structure information from the user input means 42,

Step 2202: The service management means 40 activates an application viathe input of the user to process the selected service.

In this way, in the broadcast system, the sending side transmits servicestructure information and service information containing referenceinformation while the receiving side that retains an application toperform per-service processing receives the service structureinformation and the service information to execute per-service internalprocessing.

With reference information of the contents stored in the receiver,storing/updating service structure information alone allows the samecontents to belong to a different service.

Content-based reference information describes an identifier to identifythe service (node) in the service structure information to be referencedby the contents. Thus it is possible to cause the same contents tobelong to a difference service (node) by transmitting the servicestructure information containing modified node description again byusing the identifier of the node in the previously transmitted servicestructure information. For example, assume that Content A referencesNewspaper A. By transmitting the service structure informationconstituting Newspaper A where the node of Newspaper A is changed toNewspaper A2, Content 1 belongs to Newspaper A2.

In the second embodiment, internal processing of a receiver assumed incase a viewing contract (subscription) is made per service.

When the user has selected an arbitrary node (service) from the userinput means 42 of the service receiver 30 to instruct subscription, theservice management means 40 activates an application according to theprocedure in FIG. 9 and executes the processing in the application tosubscribe to the contents that belong to the node.

The service receiver 30 changes the execution of the selected service(step 2103) in the internal processing after data reception (FIG. 8) asshown in FIG. 17.

Step 2301: The service receiver 30 determines whether the service to beinternally processed is subscribed to or not.

Step 2302: In case the service is subscribed to, the service receiver 30performs processing on the service which is subscribed to.

Step 2303: In case the service is not subscribed to, the servicereceiver 30 performs processing on the service which is not subscribedto.

In case data addition service structure information is stored in theservice structure information storage means 36 as shown in FIG. 10 andthe user subscribes to Service A, the processing in step 2302 isperformed on AV Content 1, Data Content 1 and Data Content 2, and theprocessing in step 2303 is performed on the remaining data contents andAV contents.

In this way, a receiver in this broadcast system can select services tobe subscribed to per node in the received service structure information.Also it is possible to switch internal processing per node.

In the third embodiment, a broadcast system where the contentsautomatically stored on the receiving side can be controlled on thesending side is described.

A service transmitter in the broadcast system has the same configurationas the service transmitter in FIG. 1. Information indicating whether toautomatically store the contents received on the receiving side(automatic storage flag) is input from the contents information inputmeans 12 of the service transmitter 10 (step 1204 in FIG. 4). Theautomatic storage flag is appended to the contents of serviceinformation containing reference information via the service informationadding means 14 (step 1405 in FIG. 6). FIG. 20 illustrates serviceinformation with the automatic storage flag appended.

Meanwhile, a service receiver in the third embodiment comprises anautomatic storage management means 43 for controlling the data contentsreceiving means 34 and the AV data receiving means 35 based on theautomatic storage flag appended to the service information. The otherconfiguration is the same as that of the service receiver in the firstembodiment (FIG. 1).

FIG. 19 is a flowchart showing the operation of the receiver andcorresponds to the processing procedure from step 2003 to step 2010 inFIG. 7.

On receiving data, the receiving/demultiplexing means 31 demultiplexesthe received data.

Step 4101: In case the received data contains AV data,

Step 4102: The automatic storage management means 43 determines whetherthe program composed of the received AV data is a candidate forautomatic storage from the service information that has been received.

Step 4103: In case the program is a candidate for automatic storage, theautomatic storage management means 43 stores the AV data in the AV datastorage means 39.

Step 4104: In case the received data contains data contents,

Step 4105: The automatic storage management means 43 determines whetherthe program composed of the received data contents is a candidate forautomatic storage from the service information.

Step 4106: In case the program is a candidate for automatic storage, theautomatic storage management means 43 stores the data contents in thedata contents storage means 38.

Step 4107: In case the received data contains service information,

Step 4108: The automatic storage management means 43 stores the serviceinformation in the service information storage means 38.

Step 4109: The automatic storage management means 43 extracts a programto be automatically stored from the service information storage means37.

Step 4110: In case the received data contains service structureinformation,

Step 4111: The automatic storage management means 43 stores the servicestructure information in the service structure information storage means36.

AV data stored in step 4103, data contents stored in step 4106, serviceinformation stored in step 4109, and service structure informationstored in step 4111 are output to the service management means 40 andinternal processing is performed following the same procedure as in FIG.7.

In case it can be determined that contents to be automatically stored ispresent from the service information that has been received, the timethe contents are transmitted may be reserved via timer setting and thecontents alone may be received and stored automatically.

For example, in case the service transmitter assumes data additionservice structure information as shown in FIG. 21, it transmits servicestructure information data shown in FIG. 13 and service information datashown in FIG. 20.

Meanwhile, assume that the receiving side that has received dataaddition service structure information in FIG. 21 has received DataContents 1 through 6 and AV Contents 1 through 4. In case the receivingside does not store data received as default data (except cache data)but automatically stores contents with the automatic storage flag alone,the receiving side automatically receives Data Contents 1, 4 and AVContents 2, 4 having the automatic storage flags.

Operation of automatic storage greatly depends on the application on thereceiving side. For a receiving side that assumes storage of all thereceived data, contents and AV data having the flag may be automaticallyexcluded from storage processing.

In the automatic storage of contents, update of storage is performed incase the contents identifier is identical with the contents that havebeen stored. In the update of storage, basically the over write updateis performed. In case the contents are managed by version, all thecontents of different versions may be stored even when they have thesame contents identifier.

In this way, the sending side individually appends the flag to contentsso that the receiving side automatically stores contents independentlyof the service structure information.

It is also possible to enable automatic storage of a particular node inthe service structure information on the sending side and make thereceiving side automatically store the contents that belong to the node.

By specifying a node in the service structure information and contentsthat belong to the node, it is possible to separate the operation on thereceiving side on the contents of the same node based on the type ofcontents. For example, in case setting is made to automatically storeService A in the service structure information in FIG. 21, Data Content1 that belongs to Service A is automatically stored but AV Content 1 andData Content 2 are not automatically stored. In this way, it is possibleto cause the receiving side to take action at two levels (“automaticstorage” and “non-automatic storage” and so on) for the contents thatdepend on a node in the service structure information.

For example, setting is possible where Service A in the servicestructure information in FIG. 21 is automatically stored and the servicestructure information is transmitted to the receiver of User A whileService C in the service structure information in FIG. 21 isautomatically stored for User B. In this case, by transmitting theservice structure information to the receiver of User B, it is possibleto automatically store Data Content 1 in the receiver of User A and toautomatically store Data Content 4 and AV Content 2 in the receiver ofUser B.

To transmit different service structure information per user, receivingcontract information and individual messages to receiving subscribersmay be transmitted in the EMM (Entitlement Management Massage), a dataformat used to transmit data via broadcasts.

In the fourth embodiment, the case is described where the contents of aservice subscribed to by the receiving side are a sole candidate forautomatic storage.

A service receiver in the broadcast system differs from the thirdembodiment (FIG. 18) in that the information on a service that issubscribed to is transmitted from the service management means 40 to theautomatic storage management means 43 as shown in FIG. 22.

FIG. 23 is a flowchart showing the operation of the receiver andcorresponds to the processing procedure from step 2003 to step 2010 inFIG. 7.

On receiving data, the receiving/demultiplexing means 31 demultiplexesthe received data.

Step 4201: In case the received data contains AV data,

Step 4202: The automatic storage management means 43 determines whetherthe program composed of the received AV data is a candidate forautomatic storage from the service information that has been received.

Step 4203: In case the program is a candidate for automatic storage, theautomatic storage management means 43 determines whether the programcomposed of the received AV data belongs to a service the usersubscribes to.

Step 4204: In case the program belongs to a service the user subscribesto, the automatic storage management means 43 stores the AV data in theAV data storage means 39.

Step 4205: In case the received data contains data contents,

Step 4206: The automatic storage management means 43 determines whetherthe program composed of the received data contents is a candidate forautomatic storage from the service information.

Step 4207: In case the program is a candidate for automatic storage, theautomatic storage management means 43 determines whether the programcomposed of the received AV data belongs to a service the usersubscribes to.

Step 4208: In case the program belongs to a service the user subscribesto, the automatic storage management means 43 stores the data contentsin the data contents storage means 38.

Step 4209: In case the received data contains service information,

Step 4210: The automatic storage management means 43 stores the serviceinformation in the service information storage means 37.

Step 4211: The automatic storage management means 43 extracts a programto be automatically stored from the service information storage means37.

Step 4212: In case the received data contains service structureinformation,

Step 4213: The automatic storage management means 43 stores the servicestructure information in the service structure information storage means36.

AV data stored in step 4204, data contents stored in step 4208, serviceinformation stored in step 4211, and service structure informationstored in step 4213 are output to the service management means 40 andinternal processing is performed following the same procedure as in FIG.7.

In case it can be determined that contents to be automatically stored ispresent from the service information that has been received and that thecontents is subscribed to by the user, the time the contents aretransmitted may be reserved via timer setting and the contents alone maybe received and stored automatically.

For example, in case the service transmitter assumes data additionservice structure information as shown in FIG. 21, it transmits servicestructure information data shown in FIG. 13 and service information datashown in FIG. 20.

Meanwhile, assume that the user has selected (subscribed to) Service Cprovided by Contents Provider 1 on the receiving side that has receiveddata addition service structure information in FIG. 21. The dataaddition service structure information in this case is shown in FIG. 24.Bold lines show the services the user subscribes to and thecross-hatched section the data with the automatic storage flag appended.

Assume that Data Contents l through 6 and AV Contents 1 through 4 arereceived on the receiving side. In case the receiving side does notstore data received as default data (except cache data) butautomatically stores contents with the automatic storage flag alone, thereceiving side automatically receives Content 4 and AV Data 2 thatbelong to Service C.

In doing so, it is possible to store real data of Content 4 and AV Data2 that belong to Service C from Contents Provider 1 as shown in FIG. 25.

Operation of automatic storage greatly depends on the application on thereceiving side. For a receiving side that assumes storage of all thereceived data, contents and AV data that belong elsewhere than theselected Service C may be automatically excluded from storageprocessing.

In the fifth embodiment, some of the forms of services provided by abroadcast system according to the invention will be described.

FIG. 26 shows a case where the contents storage area on the receivingside is exclusively managed per node (News, Sports, Drama) in theservice structure information. Exclusive management of the storage areameans management of each area in an independent way without invading thestorage area of each other.

In this case, the sending side transmits:

-   (1) Service structure information shown in FIG. 26 and-   (2) Service information storing reference information and contents    information. The receiving side receives data (1) and (2) then    executes an application to exclusively manage the storage area per    node in the service structure information based on the received    data.

Via this, contents that belong to respective services of contentsproviders are stored in specified storage areas and the same contentsare updated, for example, contents that belong to Service “News”provided by Contents Provider 1 are stored in Storage Area A andcontents that belong to Service “Sports” in Storage Area B.

Thus, it is possible to prevent all the stored data from being the Newscontents or Sports contents. Respective storage areas are not invaded byother contents providers either.

FIG. 27 shows the processing to specify the same validity term ofcontents in a group by activating an application for managing thevalidity term of contents based on the information on the validity termdescribed in the contents in case such an application is owned by thereceiving side.

Contents in data addition service structure information shown in FIG. 27have respective validity terms. Content 2 belongs to Node “News” as wellas Node “Sports.”

In this case, the sending side sending side transmits:

-   (1) Service structure information shown in FIG. 27-   (2) Service information storing reference information and contents    information. The receiving side receives data (1) and (2) then    executes an application to exclusively manage the storage area per    node in the service structure information based on the received    data.

The receiving side that owns this application can manage contentsrelated to “News” based on the validity term of Content 1. That is, thevalidity term of Content 2 is originally Oct. 10, 1999 while it may bechanged to Oct. 2, 1999 in a group called “News.”

In doing so, in case contents that reference each other via a linkprovided between Content 1 and Content 2 are mutually essential, thesecontents may be grouped as contents having the same validity termrelated to “News.” The validity term of Content 1 may be set to Oct. 10,1999 in conformity with the validity term of Content 2.

Similarly, in case Content 2 and Contents 3 as contents related to“Sports” are mutually essential, the validity term of Content 1 andContent 3 may be set to Oct. 10, 1999 in conformity with the validityterm of Content 2. The validity term may be changed depending on whichof “News” or “Sports” Content 2 belongs to.

Thus, in case the validity term of a group that accommodates contents isgiven priority rather than the validity term of the contents, thevalidity term management method is applicable.

In this way, when the validity term of contents are determined, it isnot necessary to append a validity term to a node in the servicestructure information.

FIG. 28 shows a case where the receiving side owns an application tocalculate the price of a node (service) from the price of contents andcalculates the price of a service from the price of contents.

In this case, the sending side transmits:

-   (1) Service structure information shown in FIG. 28 (excluding the    information on the piece of service) and-   (2) Service information storing reference information and contents    information (contents information includes the information on the    price). The receiving side receives data (1) and (2) then executes    an application to calculate the price of a node (service) from the    price of contents.

In this way, by providing an application to calculate the value of Newsfrom the values of Content 1 and Content 2, it is not necessary todescribe the value of each node in the service structure information. Incase contents that belong to News have increased in number, only theadditional contents have to be transmitted without a need to modify theservice structure information itself, thus upgrading the transmissionefficiency.

FIG. 29 shows a case where the receiving side owns an application toexclusively manage the storage area per node in the service structureinformation and the sending side specifies a service (News, Sports) tobe managed exclusively.

In this case, the sending side transmits:

-   (1) Service structure information shown in FIG. 29 and-   (2) Service information storing reference information and contents    information. The sending side incorporates the information to    specify a particular node (News, Sports) in the service structure    information being transmitted. The receiving side receives data (1)    and (2) then executes an application to exclusively manage the    storage area per node in the service structure information based on    the received data.

The following describes a case where the sending side knows theinformation to identify the storage area from each node in the servicestructure information in advance and directly specifies the storage areaof the receiving side by using the information.

The receiving side, based on the information from the sending side,stores contents that belong to News and Sports of Contents Provider 1 inStorage Area A and Storage Area B respectively, as shown in FIG. 29. Thereceiving side stores the remaining contents in Storage Area C. Thereceiving side updates the same contents already in a storage area.

Thus, it is possible for the sending side to specify the storage area onthe receiving side per group. This allows the sending side to transmitcontents according to the capacity of the specified storage area.

For correspondence between each node in the service structureinformation and a storage area, it is possible to describe on the nodethe capacity of a storage area for storing the contents that belong tothe node. Storage are as may be separate between contents providers.

In case the receiving side owns an application to manage the validityterm of contents per service in FIG. 27, the sending side transmits:

-   (1) Service structure information shown in FIG. 27 (validity term is    set as an attribute of the element or node) and-   (2) Service information storing reference information and contents    information. The transmitting side incorporates the information to    specify a particular node (News) in the service structure    information being transmitted so that the receiving side can manage    the validity term of contents per node in the received service    structure information.

The validity term specified per contents is neglected. For example, incase the information “valid until Dec. 1, 1999” is set as an attributeof News in the service structure information in FIG. 27, the validityterm of Content 1 and Content 2 will be Dec. 1, 1999.

In this case, it is not necessary to describe a validity term percontents but to describe a validity term in the service structureinformation for grouping the contents. This reduces the volume ofdescription thus upgrading the transmission efficiency.

Information may be appended to a node in the service structureinformation in order to “enable the contents until the storage area isfull” as a validity term of contents that belong to the node in theservice structure information and the receiving side may install acorresponding application.

In FIG. 29, the receiving side can own an application to exclusivelymanage the storage area per node in the service structure informationand the receiving side can specify a node (News, Sports) to exclusivelymanage the storage area so that the contents that belong to the node canbe stored in a particular storage area in the receiver.

In this case, the sending side transmits:

-   (1) Service structure information shown in FIG. 29 and-   (2) Service information storing reference information and contents    information). The receiving side specifies a particular node in the    service structure information and executes the aforementioned    application to store the contents that belong to the specified node    in a particular storage area of the receiver or to update the same    contents already in a storage area.

For example, the receiving side can receive the service structureinformation shown in FIG. 29 then the user can allocate contents thatbelong to News and Sports in Storage Area A and Storage Area Brespectively, and store the remaining contents in Storage Area C.

By doing so, the user on the receiving side does not manage contentswithout knowing the structure of contents but uses the service structureinformation from the sending side and contents management by the sendingside to manage contents.

FIG. 30 shows a case where the receiving side owns an automatic storageapplication and automatically stores particular contents. Note thatautomatic storage in the invention covers automatic storage of contentsand automatic update of the same contents (in case the contentsidentifier is the same or both the contents identifier and the contentsversion are the same).

In this case, the sending side transmits:

-   (1) Service structure information shown in FIG. 30 and-   (2) Service information storing reference information and contents    information. The sending side incorporates the automatic storage    flag of the contents (Content 1, Content 3) in the contents    information in the service information being transmitted. On    receiving the data, the receiving side executes the automatic    storage application.

The receiving side automatically stores Content 1 and Content 3 thathave been received. The receiving side does not automatically storeContent 2 that has been received but display the subscription guide toNewspaper A or store the subscription guide alone. The receiving sidedoes not automatically store Content 4 that has been received but storesthe subscription guide to Newspaper C.

In case the receiving side has received content that are notautomatically stored, the receiving side may store or present thesubscription guide to the service referenced by the contents as well asthe information on the service referenced by the contents. Thus, anyoperation except storage of contents is allowed.

A form is possible where, for example, the subscription guide toNewspaper A and the guide to Content 2 are stored on receiving Content1, no operation is performed on receiving Content 2, the subscriptionguide to Newspaper B is stored on receiving Content 3, and no operationis performed on receiving Content 4.

In case Content 2 and Content 4 perform content-based charging, it ispossible to announce that some contents in Newspaper A and Newspaper Care not automatically stored or updated when Content 2 and Content 4 arereceived.

In this case, contents can be automatically stored independently of theservice structure information. When contents are received, action may betaken utilizing the service structure information at two levels,“automatic storage” or “non-automatic storage,” and “subscription guideutilizing service structure information” or “no operation” and so on.

FIG. 31 shows a case where the sending side sets automatic storage ofcontents and automatic storage on nodes and the receiving side owns anautomatic storage application to perform automatic storage processing.

In this case, the sending side transmits:

-   (1) Service structure information shown in FIG. 31 and-   (2) Service information storing reference information and contents    information (the automatic storage flags for the contents, Content    1, Content 3 are stored in the contents information in the service    information). The sending side incorporates the information on a    particular node (Newspaper A) that may be automatically stored in    the service structure information being transmitted.

On receiving the data, the receiving side executes an automatic storageapplication. The receiving side, on receiving Content 1, automaticallystores or updates Content 1 and uses Content 1 as Newspaper A, sinceboth service structure information and contents can be automaticallystored. The receiving side, on receiving Content 2, displays thestorage/update guide or store the subscription guide alone, since onlythe service structure information (Newspaper A) can be automaticallystored. The receiving side, on receiving Content 3, automatically storesor updates Content 3 but cannot use Content 3 as Newspaper B, since thecontents alone can be automatically updated. The receiving side, onreceiving Content 4, performs no operation since Content 4 cannot beautomatically stored.

The receiving side, on receiving Content 3, may not automatically storeContent 3, since Newspaper B to which Content 3 belongs cannot beautomatically stored.

The receiving side, on receiving Content 3, may display the subscriptionguide to Newspaper B.

In this way, the receiving side can automatically store contents thatbelong to a node in the service structure information specified by thesending side and use the contents as contents that belong to the node.The receiving side, on receiving contents for a node n the servicestructure information on which the contents are dependent, can takeaction at one of the four levels as appropriate.

FIG. 32 shows a case where the receiving side subscribes to a particularnode.

In this case, the sending side transmits:

-   (1) Service structure information shown in FIG. 32 and-   (2) Service information storing reference information and contents    information (the automatic storage flags for the contents, Content    1, Content 3 are stored in the contents information in the service    information). The receiving side executes an automatic storage    application as well as sets subscription to a particular node in the    service information (Newspaper A).

Then the receiving side automatically stores or updates Content 1 butdoes not automatically store the remaining contents.

In this way, the user can select an arbitrary node in the servicestructure information from the sending side to automatically store thecontents that belong to the node, thereby reducing the load of operationof the user on the receiving side. The sending side can permit the userthat has selected a node to automatically store contents.

In case a contents provider provides the same contents to a plurality ofbroadcast stations, it is possible to make effective the storage ofcontents on the receiving side by transmitting the service structureinformation as shown in FIG. 33. Each node in the service structureinformation indicates that the same contents reference the node. Thesending side transmits the service structure information together withservice information storing reference information and contentsinformation.

The service structure information indicates for example that Content 1and Content 2 are identical as Content A even though the value ofCONTENT_ID to identify the contents differs between Content l andContent 2. The receiving side executes an application that processeseach content that references the node contents as the same content inorder to avoid duplicated storage. Contents Provider 1 does not have touse a single CONTENT_ID value to identify contents between broadcaststations when broadcasting Content A from a plurality of separatebroadcast stations. Reference to Content A of a node in the servicestructure information indicates that Content 1 and Content 2 are thesame so that it is not necessary to match CONTENT_ID.

Assume Broadcast Station A has broadcast Content A by using CONTENT_ID=1(Content 1) and Broadcast Station B has broadcast Content B by usingCONTENT_ID=2 (Content 2). In this case, the receiver must store ContentA as Content 1 and Content 2 separately in case an application is notavailable that determines the identity of the service structureinformation or contents shown in FIG. 33. Once such an application isprovided, it is possible to store either Content 1 or Content 2 asContent A, thereby allowing efficient use of storage capacity.

A contents provider has only to manage the structure of contents and abroadcast station to manage transmission of contents, thus allowingmanagement to be shared without knowing the structure of each other thusupgrading the work efficiency. It is possible to provide a rule todelete an unnecessary content in case seemingly separate contents aredetermined to be the same and to delete either of the contents accordingto the rule. This allows efficient use of storage capacity.

Similarly, in case contents are stored in the receiving side in advance,or pre-installed, and the reference information of the contentsreferences a particular node in the service structure information andthe contents provider knows the identifier to identify the referencednode, it is possible to use the node to utilize the service structureinformation in order to show that the pre-installed contents is the sameas the contents about to be sent.

While the upper layer of Content A is Contents Provider 1 in FIG. 33, alayer of information to group contents maybe inserted between ContentsProvider 1 and Content A or Content B and so on.

In the sixth embodiment, a particular example is described where serviceinformation storing service structure information, reference informationand contents information is transmitted by using SI.

As shown in FIG. 34(a), three storage-based broadcast applications,Service A, Service B, and Service C from the contents provider(information provider) A are displayed on the selection screen of thereceiver and the user selects viewing of desired contents on the screen.FIG. 34(b) shows stored contents that can be viewed in case each serviceis selected. For example, selecting Service A on the screen allowsviewing of Content A and Content B already stored in the receiver.

To implement such a storage-based broadcast application by using ERT,event_relation_id and relation_type of the ERT defined as a standard aredefined as shown in FIG. 43 in order to show that the ERT is a“storage-based broadcast service” and its structure is “presentedservice description” (indicating service structure information).

The ERT (Event Relation Table) is described in Chapter 3, the ARIBSTD-B10 version 1.2. The data structure of the ERT is shows in FIG. 46.

An information provider (Company A) must make information providerdefinition as to items shown in FIG. 36. Such items are informationprovider identifier of Company A, ID of the service to be provided(node), information providers the contents are related to, reference toevents and nodes. Note that the information provider identifier may bepredetermined in terms with other information providers.

In this embodiment, service structure information is transmitted usingthe ERT of SI. The identifier to identify the information provider(contents provider) is represented by using information_provider_id, theidentifier to identify the type of broadcast service by usingevent_relation_id in the ERT, and the identifier to identify the serviceprovided by the information provider by using node_id in the ERT.

FIG. 37 shows an example where service structure information consistingof Information Provider A, Service A, Service B and Service C isdescribed in the ERT.

Contents reference information is described in the reference descriptorof SI. The reference information descriptor is described in Chapter 3,the ARIB STD-B10 version 1.2. The data structure of the referenceinformation descriptor is shown in FIG. 47. FIGS. 39, 40 and 41 showexamples of creation of reference information descriptors for Contents Aand B, C, and D, respectively. An information provider may be the sameas a broadcast operator.

Reference information of the contents described in the referenceinformation descriptor is passed from an information provider to abroadcast operator in advance. The broadcast operator, on receiving theinformation, allocates contents identifiers (content_id) to thecontents. FIG. 38 shows an example thereof.

The reference information descriptor is stored in the EIT data contentsdescriptor (selector area) (refer to Chapter 2, ARIB STD-B10) and theEIT data contents descriptor is stored in the position where adescriptor in EIT is stored for transmission. FIG. 44 shows the datastructure of EIT. FIG. 45 shows the data structure of the EIT datacontents descriptor. FIG. 42 shows the structure arib_bxml_info ( ) as adescription example of the selector area of the EIT data contentsdescriptor. In content_id is described the identifier of the contentswhere reference information is described in the reference informationdescriptor. It is possible to describe more than one referenceinformation descriptor for a single content.

A receiver that has received the ERT and the EIT data contentsdescriptor can reproduce service structure information from the ERT andreproduce the information on the node (n#10), event (e#1) andinformation provider (i#1) to which each content is related as shown inFIG. 35. This obtains data addition service structure information.

In this way, by using SI such as ERT and reference informationdescriptor, it is possible to transmit service structure information andservice information service information storing service structureinformation, reference information and contents information to thereceiving side.

In the seventh embodiment, a case is described where automatic storageinformation is transmitted to the receiving side by using the EIT datacontents descriptor.

The arib_bxml_info ( ) structure of the selector area of the EIT datacontents descriptor is expanded as shown in the cross-hatched section inFIG. 42 so that the viewer can store contents easily even in case thebroadcast operator is different from the contents provider.

Extended items as follows:

auto_storage_flag (automatic storage flag): Indicates whether toautomatically store the contents. When the value of auto_storage_flag is0, automatic storage of contents is not executed. When it is 1, thecontents are automatically stored via the reference informationdescriptor concerning the subsequent provision of contents. Timing forautomatic storage (at EIT reception or program selection) depends on thereceiver used.

content_provider_flag (contents provider flag): Indicates whether theoperator providing the contents is the same as the broadcast operatorbroadcasting the contents. When the value of content_provider_flag is 0,this field indicates that the operator providing the contents is thesame as the broadcast operator broadcasting the contents or there is noneed to describe a contents provider. When the value ofcontent_provider_flag is 0, this field indicates that the operatorproviding the contents is not the same as the broadcast operatorbroadcasting the contents.

content_provider_descriptors_length (contents provider descriptor looplength): This is a 12-bit field to specify the total byte length of thesubsequent descriptors.

descriptors ( ): In case the operator providing the contents is not thesame as the broadcast operator broadcasting the contents, this fieldstores a reference information descriptor to indicate the contentsprovider. A plurality of reference information descriptors may bestored.

A receiver that has received data contents represented by content_id(contents identification: 32-bit field to identify the data broadcastprogram) in case file_storable_flag (file storable flag: Flag toindicate whether the data broadcast program can store files) inarib_bxml_info( ) of the EIT data contents descriptor is 0 andauto_storage_flag is 1 automatically stores the contents in case theevent relation identification (event_relation_id: Identifies serviceform type), information provider identification(information_provider_id: Identification of operator that provides thecontents) and node identification (node_id: Identifies the providedservice) are identical with these identifications registered in thereceiver.

Assume, for example, via reception of ERT, the storage-based broadcastservice (binary data) has been registered in the receiver as theevent-related identification (service form type), the storage-basedbroadcast service operator A (binary data) as the information provideridentification (information provider), and Service A (binary data) asthe node identification (provided service).

In case auto_storage_flag of the EIT data contents descriptor of thereceived contents island “storage-based broadcast service,”“storage-based broadcast service operator A,” and “service A” aredescribed in the contents, the contents are automatically stored in thereceiver.

In case auto_storage_flag of the EIT data contents descriptor of certaincontents is 1 and “storage-based broadcast service,” “storage-basedbroadcast service operator A,” and “service B” are described in thecontents, the contents are not automatically stored.

In this way, it is possible to instruct automatic storage on thereceiving side by using the EIT data contents.

As understood from the foregoing description, a broadcast systemaccording to the invention allows per-service contents management.

It is possible to perform per-service control from the sending side tothe receiving side, and to exclusively control storage areas on thereceiving side per service or control the validity term of contents perservice.

It is possible for the receiving side to use service structureinformation sent from the sending side to perform per-service contentsmanagement, control storage areas on the receiving side per service orcontrol the validity term of contents per service.

By appending the automatic storage flag to contents, it is possible tomanage contents that belong to a service in combination with theautomatic storage flag.

By using the service structure information to determine the identity ofthe contents to be broadcast, it is possible to identify contents viaonly an identifier to identify a node in the service structureinformation to be generated on the receiving side without consideringthe information used by contents providers or broadcast operators toidentify contents in data transmission. On the receiving side, it ispossible to recognize the contents transmitted between differentbroadcast stations as the same contents or recognize the pre-installedcontents to be the same as the contents about to be broadcast. Thismakes efficient the storage processing and storage capacity.

1. A transmitter of a storage-based digital broadcast system,comprising: service structure information generating means forgenerating service structure information representing a relationalstructure between services provided by contents providers, referenceinformation generating means for generating reference information forassociating the contents with the service described in said servicestructure information, service information adding means for adding saidreference information to service information, and transmission means fortransmitting service information containing said reference information,said service structure information and the contents.
 2. A transmittingmethod of a storage-based digital broadcast system, comprising the stepsof: generating service structure information representing a relationalstructure between services provided by contents providers, generatingreference information for associating the contents with the servicedescribed in said service structure information, adding said referenceinformation to service information, and transmitting service informationcontaining said reference information, said service structureinformation and the contents.
 3. A receiver of a storage-based digitalbroadcast system, comprising: demultiplexing means for demultiplexingcontents, service structure information describing the relationalstructure between services provided by contents providers and serviceinformation containing references information associating contents withthe service described in said service structure information fromreceived signals, contents storage means for storing demultiplexedcontents, service structure storage means for storing demultiplexedservice structure information, service information storage means forstoring said demultiplexed service information and, service managementmeans for managing storage of said contents by using service structureinformation and reference information in said service information.